The present invention generally relates to composite materials, and in particular, to composite materials having two or more layers of high modulus fiber layers.
There is significant interest in the development of lightweight, durable and inexpensive structural composites suitable for use in various applications, such as truck trailer floor and side panels, automotive interior components, residential and commercial building materials, and so on. Sandwich composite materials containing thin, high strength skins adhesively bonded to a thicker, lightweight core material are generally used. The core material should be sufficiently stiff, have good shear properties, be capable of distributing loads over a large area, and provide good adhesion to the skin layers adjoining it.
The skin materials are typically formed of a fiberglass reinforced plastic. Honeycomb structures have been a commonly used core material as they provide exceptional specific rigidity. However, honeycomb core materials do not provide a full surface for lamination and are prone to delamination, face buckling or catastrophic failure. Also, sandwich composite structures containing honeycomb cores may have difficulties being molded into complex three-dimensional geometries.
Thus there is a need for a light-weight, stiff, energy absorbing and moldable core material for sandwich panel composites. The fibrous composite core material described in this invention can be molded into complex three dimensional shapes in addition to providing a full surface for lamination and fastener applications.